Bobbin-holder for rotary-hook machines.



R. K. HOHMANN. BOBBIN HOLDER FOR ROTARY HOOK MACHINES.

v APPLICATION I"ILED MAY5, 19.13. 1,105,1 97.

, Patented July 28, 1914.

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RICHARD K. HOHMANN, OF BELVDEIt-E. ILLINOIS, ASSIGNOR TO NATONAL SEWING MACHINE COMPANY, OF BELVIDERE, ILLINOIS, A CORPORATION 0F ILLINOIS.

BOBBIN-HOLDEB. FOR- ROTARY-IGGK MACHINES.

Application filed May 5, 1913.

Specification of Letters Patent.

atentcd July 2S,

sel-iai No. 765,419.

MANN, a citizen of the United States, residing at Belvidere, county ot Boone, State ot' lllinois, have invented certain new and use ful Improvements in Bobbin-l'lelders for otary-llook Machines, of which the t'ollowing` is a specification. i

This invention relates to the holder or race which carries the bobbin containing the lower thread in revolving hook sewing ma chines. y

Une purpose of the invention is to econo-y mize space, making it possible to use a larger bobbin carryinga much larger amount of thread than has been possible with races of the same size in any previous construction known to me.

A further object of the invention is to place proper tension on the thread carried by the bobbin by `simple mechanisminvolving nothing more than the retaining means for the bobbin.

The novel features of the invention willV be apparent from the following description taken in connection with the drawings.

1n the'drawings: Figure 1 is a side view ot' a bobbin holder embodying myinvention. Fig. 2 is a c'ross section on the line 2-2 of Fig. 1.

It is of course Well known that in revolving hook sewing machines the bobbin for the lower thread is carried in a race or holder around which the revolving hook moves, the loop of thread being carried by the revolvi-ng hookl and spread around the bobbin holder so-.as to form the loek stitch, the upper thread interlocking with the lower thread. '1n the present case I have shown only the bobbin holder but am ling another application herewith relating; to the particular machine in which this holder is used, and since' thosel skilled in theart will understand the necessary features of the invention which cooperate with the bobbin holder itl is not necessary to show those features in the present case.

As shown in theI drawingsmy bobbin holder or race includes a casing having aL circumferential bearingrim 1 which serves fto support the holder when it is in use in the machine, this bearing rim fitting in a bearing groove,- and the holder being held by means, not shown,'for preventing it trom rotatingas the revolving hook passes around it. ln the torni shown the bearing rim 1- is cut away at the top and a hook 2 is formed near the top on one Side facingthe top so as tocatch and spread the thread as it is being carried around the holder. The holder has a. rear wall 3 and opposite that Wall in the tace ot the holder vthere is an opening circular in forni ot the right size to receive the bcobin 4. not concentric. with the bearing riml, but, onthe contrary, is arranged eccentric thereto, its axis being to one side 'of and in substantially the same horizontal plane as the axis ot the bearing rim. 'The end walls 5 and G are inclined from the hearing rim outwardly to the edge of the circular bobbin holdingn space, and since the hobbin is eccentrically arranged in the holder the walls 5 and 6 will not be at such a steep inclination as the walls 7 and S on the opposite side of the holder nearest Athe bobbin'space. A hollow column or shaft 9 is secured-to the rear wall 3 centrally of the hohbin space and it projects toward snchwopening in the opposite wall and is adapted to receive the bobbin 4*, which has the central hearing openingfit' ting' this shaft. is will be seen by reference to Fig. 2 the shaft 9 is somewhat shorter than the bobbin so that the end wall of the bobbin is somewhat `beyond the end of the shaft. ln order to hold the bobbin in placeA in the holder and to give it the necessary tension a spring 1Q is used within hollow shatt- 9 and a member 11 extends down into that shaft and is adapted to be pressed inwardly by the spring. A retaining arm 12 is pivoted at 13 to thc end ot the member 11 and is adapted to be turned down to the position shown in Fig. 1, extending downwardly at an angle or' about 450 on the same side of the holder as that on which the hook 2 is placed. This arm can be turned up until it is in line with the member 11 and then the hook or bobbin can be removed from the shaft 9. 1When turned down to the position Vshown in the drawing its 'face bears` against the'euter face of the bobbin 4, and since the spring 1() tends at all times to draw it inward it will bear against'the bobbin with a yielding pressure, thus causing;- t'rietion and operatinnto cause tension on the'thread as it is drawn 'troni the bobbin. The end ot the arm 12 is bent downwardly over the edge ot the bobbin, as shown in Fig, 2, so as tobe out of the way Within the casing to prevent This circular opening is Il O is being draivn up there is not the same ne-` cessity for preventing a steep angle. ln othervfords the thread can be pulled ott of the holder on a sida Where the Wallsappreach the' vertical quite closely, as shown in 2. l have found therefore that by placing the bobbin eccentrically and on the side Where the thread will be when being drawn' up I am enabled to use a much larger bobbin in a holder of the same circumference, and l have found that .it does not aliect in any way the smooth and free operation o the take-up. The single arm l2 is used as the retaining means and the tension means7 this being rendered possible by the arrangement ot the arm at the angle of 45o, as shown, whereby the loop of thread will first strike the outer end of the arm and simply travel up along itand will not be caught by its side er the opposite end.

l-laving thus described the invention what is claimed as new is:

il. It. bobbinholder tor rotary hook sewin machines comprising a casing having a cirounitcrential bearing rini formed with a hook and having a circular' opening in one side Wall to admit a bobbin, the said opening being eccentric to the bearing rim and being more widely separated Afrom that portion of the bearing rim imi'ncdiately behin said hook than from the diametrically opposite portion ofsaid rim, the sidewalls extending on an incline from the margin of said Openlling to the bearing rim, whereby the side walls in that part behind the hook will have a less inclination to the plane of the rim .than in the part on the opposite side.

Q. A bobbin holder for rotary hook sewing machines comprising a casing having a v circumferential bearing rim formed with a' clination toward the plane of the rim than the walls in other portions of the holder.

3. A bobbin holder for rotary hook sewing machines comprising a, casing having a circumferential bearing rim extending throughout the major portion of a circle, and a circular opening in one side wall to admit a bobbin7 the said opening being eccentric to said bearing rim, and the side walls heilig inclined from said rim to the edge of said bobbin holding opening the inclination ot the Walls being materially greater on one side of the axis of the holder than on the other.

. 4. A bbbin holder for rotary hook sewing machines comprising a -casing having a` circumferential bearing rim formed with a hook near the top facing the top and having a circular opening in one side Wall to admit a bobbin, the said opening being eccentric to said bearing rim and its axis being in substantially. the same horizontal plane the axis of the rim and on the side opposite to that carrying the hook.

A bobbin holder for rotary hook sewing machines comprising a casing having a circumferential bearing rim formed with a .hook near the top facing the top and having acircular opening in one side Wall' to admit a bobhin, the said opening being eccentric to said bearing rim and its axis being in substantially the same horizontal plane as the axis of the rim and on the side opposite to that carrying the hook, a. hollow shaft carried by the rear wall of said casing and extending centrally of said opening and adapted to carry the bobbin, a spring retained member insaid shaft, a retaining arm pivoted to said member and adapted to lie across said opening extending downwardly at an angle of about 'forty live degrees on the side carrying the hook.

(5. Tn a device ot the class described, the combination with a casing having` an opening in one side to receive a bobbin, acircumferential bearing rim having a hook at one vside near the top facing the tcp` a bobbin supporting shaft centrally ol. said opening, a retaining arm carried by said shaft and extending downwardly at an angle of about forty live' degrees on the side carrying the hook, and spring pressed means carried by said shaft for pulling said arm inward against the bobbin so as to retard its turning movement andy to place the necessary 4 tension on the thread.

In testimony whereof I aiiix my signature in presence of two Witnesses.

RICHARD K. HOHMANN.

Witnesses:

ARTHUR L. BRYANT, Lon T-T, CADARR. 

